Hardness tester



W. A. WILLIAMS HARDNESS TESTER June 25, 1968 5 Sheets-Sheet 1 Filed July 15. 1964 INVENTOR ATTORNEYJE United States Patent Office 3,389,597 Patented June 25, 1968 3,389,597 HARDNESS TESTER William A. Williams, 316 E. Wadsworth St., Philadelphia, Pa. 19119 Filed July 15, 1964, Ser. No. 382,767 6 Claims. (Cl. 73-81) This invention relates to improvements in hardness testers of the general type represented by my Patent No. 2,448,645, dated Sept. 7, 1948. References are also made to my patents, No. 2,466,567, dated Apr. 5, 1949; and No. 2,544,205, dated Mar. 6, 1951. Each of the devices represented by the said patents was capable of testing only small or intermediate size specimens or was limited to testing only specimens of magnetic materials.

An important object of the present invention is to provide an apparatus capable of making hardness tests of specimens of very large size, as well as of small size, and of any solid material.

A further object of this invention is to provide a hardness tester in which the specimen is uniformly pressed against an anvil when held in position for testing,

Another object of this invention is to provide a specimen holding mechanism for a hardness tester which is provided with flexibility so that the specimen will be uniformly pressed against an anvil.

A further object of this invention is to provide for universal flexibility between the specimen holder and the anvil against which the specimen is pressed.

A further object of this invention is to provide a hardness tester having a specimen holder provided with elastic means between the anvil and a specimen clamping means.

Still another object of this invention is to provide an anvil, against which the specimen is pressed when being tested with a passageway for passage of a penetrator.

In the accompanying drawings several embodiments of the invention are represented.

In the drawings:

FIGURE 1 is a side elevational view of a hardness tester employing a large C-clamp for holding the specimen.

FIGURE 2 is an enlarged cross-sectional, side elevational view of a detail of FIG. 1.

FIGURE 3 is a diagrammatic, side elevational view of a hardness tester employing a parallel motion type of clamp, with certain conventional parts omitted in the interest of clarity.

FIGURE 4 is a side elevation of an embodiment of a hardness tester employing a flexible link chain for pressing the specimen against the anvil, certain parts being broken away in the interest of simplicity of illustration.

FIGURE 5 is a cross-sectional view on line V--V of FIG. 4.

FIGURE 6 is an enlarged cross-sectional view of the chain take-up and tensioning mechanism of FIG. 4.

FIGURE 7 is a cross-sectional view on line VlIVlI of FIG. 6.

FIGURE 8 is an enlarged cross-sectional view of a detail of a chain-end holding mechanism showing a roller type chain.

FIGURE 9 is an enlarged cross-sectional view of the anvil and penetrator arrangement taken on line IXIX of FIG. 4.

FIGURE 10 is an enlarged detail view partly in section of the center cross bar, on line X--X of FIG. 9.

As initially pointed out, the present invention relates to improvements on patented hardness testers and accordingly some of the elements may be similar to known elements and are represented only diagrammatically and need not be described in full detail.

In FIG. 1 of the drawing a hardness tester is shown having a C-shaped frame 1, provided with a boss 2 at one of its end portions 4. A handle 5 is secure-d to boss 2 by any suitable means, such as welding. The boss 2 has an axial aperture serving as a bearing for the screwthreaded spindle 6 of specimen penetrator 8. The boss 2 is provided with an axially outward extension 7 which is threaded interiorly and in which the screw-threaded spindle drivingly engages.

Numeral 9 indicates a graduated cylinder mounted on an axial tubular hub extension 10 of hand wheel 11 operatively connected to the outer end of spindle 6.

A transparent plate 12 is stationarily mounted on boss 2, and is provided with an indicating arrow 14 which cooperates with the graduations of cylinder 9.

A load indicator 16 of any suitable commercial construction is mounted on the free end portion of an arm 17 fixedly attached to a boss 19 at the other end 20 of C- frame 1. The load indicator is provided with a graduated scale 21 and a pointer 22 actuated by a. plunger 24 engaged with extension 7 of boss 2. The load indicator indicates the load by measuring the deflection of end 20 of the C-shaped frame 1 during a hardness testing operation.

The mechanism, thus far briefly described, is similar to that disclosed in my Patent No. 2,448,645 previously referred to herein.

As is obvious from an inspection of said Patent No. 2,448,645 the tester disclosed therein suffers from the drawback that the specimens to be tested cannot exceed in size the span of the C-shaped frame.

According to the present invention the boss of the other end of C-frame 1 is provided with a. through-extending axial opening 25 through which extends the hollow shank portion 26 of anvil 27 the specimen engaging portion 29 of which faces away from C-frame 1.

A comparatively large C-shaped clamp 30 is attached by one end portion thereof with the end portion of the Gimme and, thus, with the anvil in such manner as to allow a certain amount of flexing between the anvil and said clamp. To this end the inner face 31 of the boss 19 of the C-frame 1 is convexly rounded, that is, semi-spherical as indicated at 31. The adjacent end portion of C- clamp 30 is provided with an opening 32 and is mounted on the C-frame 1 with the shank 26 of the anvil extending through said opening. The end of said shank of said anvil opposite said anvil proper is screw-threaded as indicated at 34 and a nut 35 is threaded thereon to hold the connection between the Gimme and the C-clamp assembled. To aid in the relative flexibility between said frame and said clamp, the inner face 36 of said end portion 20 of the C-clamp is chamfered as indicated at 37 to facilitate sliding on the rounded portion 31 of the C-frame 1, and its opposite face 39 is provided with a recess 40 in which is seated an elastic bushing 41, for instance, a rubber bushing. It will, thus, be possible for the C-frame and C- clamp to flex sufliciently in any direction relative to each other to ensure that the specimen being tested will press flatly and uniformly on the anvil when clamped thereon by C-clamp.

The opposite end portion 42 of C-clamp 36 is provided with an axial opening 44 which is interiorly screwthreaded, as indicated at 45 and a screw-threaded shaft 46 extends through said opening, and is provided with uni versally swingable pressing head piece 47 for engaging a specimen and pressing it uniformly on anvil 27.

In operation the specimen to be tested is clamped. between the pressing head piece 47 and the anvil 27. The penetrator is then advanced through opening 25 in end portion 20 of C-frame 1 into engagement with the specimen by operation of wheel 11, and the results are indicated as usual by the graduations of cylinder 9 together with pointer 22 of load indicator 16.

In the event it should be desired to test a small specimen the C-clamp 30 and the bushing 41 can be omitted from the assembly, and the anvil assembled in reversed position facing the penetrator. Also, in such event, the anvil could be substituted by a solid anvil of the kind disclosed in Patent No. 2,448,645.

In the embodiment of the hardness tester, represented by FIG. 3, instead of a C-clamp, a parallel motion clamp is used for clamping the specimen on the anvil 27a. The anvil and the connection between the clamp and the Gimme 1a are preferably similar to that shown and described in connection with the previous embodiment and particularly as shown in FIG. 2. The parallel motion clamp, however, needs no special screw-thread clamping shaft such as 46 of FIG. 1, since the parallel threadedscrew members 53 which extend through and engage in screw-threaded openings 54, 55 in clamp jaw 52 and also turnably engage clamping jaw 51 provide for the clamping of the specimen on anvil 27a. In the third embodiment of the invention, represented by FIGS. 410 inclusive, the construction of the hardness tester is similar to that of FIGS. 1, 2 and 3, except with respect to the specimen clamping mechanism. In this embodiment the specimen clamping member is in the form of either a link chain (FIG. 4) or a roller chain (FIG. 8), designated generally by 56 having one end 57 secured at 59 to a chain cross bar shown enlarged in FIG. 8. The cross bar 60 is provided with flat sides 61, 62 toward its middle portion, and this portion is provided with a transverse bore 64 through which extends a headed pin 65. This pin 65 extends beyond the cross bar 60 and its projecting part 66 is provided with a transverse bore 67 through which extends the end connecting bar 69 of chain 56.

The cross bar 60 is of reduced diameter towards its ends, thus forming abutment shoulders 70, 71 for each of a pair of side bars 72 and 74 of transverse frame 73, Which bars are provided with openings 75 in their adjacent end portions. The reduced end portions of the cross bar are also provided with annular recesses 76 into which snap rings 77 are seated to hold the side bars 72, 74 assembled with the cross bar 60 and the chain 56.

The side bars 72, 74 of frame 78 are connected together at their middle portions by a center cross bar 80. This bar is substantially fiat plate and is provided with a central opening 81 for passage of the hollow shank 26b of anvil 27b through which penetrator 8b extends. On two opposite edges of cross bar are cylindrical extensions 82, 83 which extend into openings 84 at the middle portions of side bar 72, 74, respectively, and these extensions are provided with annular grooves 85 located adjacent the outer faces of the respective side bars, and snap rings 86 are seated in said grooves to maintain the cross bar and side bars in assembled relation.

In enlarged cross-sectional view FIG. 9 can be seen how the shank 26b of anvil 27b passes through the opening 25b in an end of C-frame 1b and through the central opening 81 in cross bar 80, and how the penetrator 81) passes through the opening of anvil shank 26b. The upper end portion of shank 26b is externally threaded and a nut 88 is threaded thereon to maintain the frame 78, anvil 27b and C-frame 1b in assembled relation.

At the opposite end of frame 78 a hook 87 is provided extending from the frame for engagement with a link 89 of chain 56. This hook is carried by a chain take-up and tensioning mechanism mounted on bar 91 extending between and through side bars 72, 74 of frame 78 and held by snap rings 92 in annular grooves 94 in said rod similarly as described in connection with chain cross bar 60.

The chain take-up and tensioning mechanism comprises a screw-threaded rod 95 having the chain hook 87 attached to its free end 96. This rod extends through an opening 97 of cross bar 91 and is provided with an axially extending groove 100 into which extends a pin 101 seated in an opening 102 in bar 91 for the purpose of preventing rod 95 from turning. Rod 95 extends beyond cross bar 91 and at least its upper end portion is provided with external screw threads 104. An actuating cap member 105 fits on the upper portion of rod 95. This cap has internal threads 106 engaging the threads 104 of rod 95 and is actuated by a hand wheel 108 attached to its upper end. To prevent the cap 105 from moving longitudinally it is provided with an annular groove 107 located at a position where cap 105 is seated in an annular recess 169 in cross bar 91 and an end of a pin 110 accommodated in a bore 111 in bar 91 extends into said recess.

In this embodiment the flexibility between the specimen holding apparatus is provided in one axis by the pivoted center cross bar 80 and into the other axis by the inherent flexibility of the chain and its connection means with the anvil so that in use the specimen will be pressed uniformly and equally against the anvil.

I claim:

1. In a hardness tester, a C-shaped frame, having a test-piece penetrator, and a penetrator actuator mounted on one end portion of said C-frame, means for measuring the amount of pressure applied to the Work piece, means for measuring the amount of penetration of the work piece mounted on said frame; the other end portion of said frame having an anvil mounted thereon, said anvil being provided with a front face facing in the direction of movement of said penetrator when moving to apply pressure to the test-piece and against which front face the test-piece is held when being tested, means encompassing at least part of the test-piece and holding said test-piece against said front face of said anvil, said piece-holding means being flexibly connected to the other end of said C-frarne at a position opposite said front face of said anvil so that the test-piece is pressed against said anvil uniformly, said anvil being formed with a passageway through which said penetrator extends to contact the test-piece, whereby the pressure applied to the test-piece, in being tested, is applied to said other end portion of said C-frame and causes flexing of said C-frame, said pressure measuring means performing its operation by measuring the flexure caused in said C-frame by said pressure, said means holding and pressing the test-piece on the anvil being a C-shaped clamp having one end connected to said C-frame, and the other end provided with a screw device engaging the test-piece on the side thereof opposite said anvil.

2. A hardness tester according to claim 1, and in which said flexible connection includes a bushing of elastic material mounted between said other end of said C-clamp and said anvil.

3. In a hardness tester, a C-shaped frame, having a test-piece penetrator, and a penetrator actuator mounted on one end portion of said C-frame, means for measuring the amount of pressure applied to the work piece, means for measuring the amount of penetration of the work piece mounted on said frame; the other end portion of said frame having an anvil mounted thereon, said anvil being provided with a front face facing in the direction of movement of said penetrator when moving to apply pressure to the test-piece and against which front face the test-piece is held when being tested, means encompassing at least part of the test-piece and holding said test-piece against said front face of said anvil, said piece-holding means being flexibly connected to the other end of said C-frame at a position opposite said front face of said anvil so that the test-piece is pressed against said anvil uniformly, said anvil being formed with a passageway through which said penetrator extends to contact the test-piece, whereby the pressure applied to the test-piece, in being tested, is applied to said other end portion of said C-frame and causes flexing of said C-frame, said pressure measuring means performing its operation by measuring the flexure caused in said C-frame by said pressure, said test-piece holding means comprising a parallel motion type clamp having a pair of jaws connected by a pair of spaced screws, one of said jaws being connected with said frame by said flexible connection.

4. In a hardness tester, a C-shaped frame, having a test-piece penetrator, and a penetrator actuator mounted on one end portion of said C-frame, means for measuring the amount of pressure applied to the work piece, means for measuring the amount of penetration of the work piece mounted on said frame; the other end portion of said frame having an anvil mounted thereon, said anvil being provided with a front face facing in the direction of movement of said penetrator when moving to apply pressure to the test-piece and against which front face the test-piece is held when being tested, means encompassing at least part of the test-piece and holding said test-piece against said front face of said anvil, said piece-holding means being flexibly connected to the other of said C-frame at a position opposite said front face of said anvil so that the test-piece is pressed against said anvil uniformly, said anvil being formed with a passageway through which said penetrator extends to contact the test-piece, whereby the pressure applied to the test-piece, in being tested, is applied to said other end portion of said C- frame and causes flexing of said C-frame, said pressure measuring means performing its operation by measuring the flexure caused in said C-frame by said pressure, said means for holding and pressuring the test-piece against said anvil comprising a chain having a plurality of relatively movable links providing flexibility relative to said anvil in one direction, a beam having a central portion rockably connected with said anvil, and said chain having its respective ends connected with said beam at points on opposite sides of said rockable connection with said References Cited UNITED STATES PATENTS 458,276 8/1891 Sherman 269-275 X 660,445 10/1900 Lillicrap 73-81 2,389,030 11/1945 Dana 73-81 2,448,645 9/1948 Williams 73-81 2,466,576 4/1949 Williams 73--81 2,519,107 8/1950 Brown 269275 2,544,205 3/1951 Williams 73-81 2,643,545 6/1953 More 73-83 2,890,845 6/1959 Kiekhaefer 269--249 X 3,201,976 8/ 1965 Starrett et a1 7381 RICHARD C. QUEISSER, Primary Examiner.

JAMES J. GILL, Examiner.

C. I. MCCLELLAND, Assislant Examiner. 

1. IN A HARDNESS TESTER, A C-SHAPED FRAME, HAVING A TEST-PIECE PENETRATOR, AND A PENETRATOR ACTUATOR MOUNTED ON ONE END PORTION OF SAID C-FRAME, MEANS FOR MEASURING THE AMOUNT OF PRESSURE APPLIED TO THE WORK PIECE, MEANS FOR MEASURING THE AMOUNT OF PENETRATION OF THE WORK PIECE MOUNTED ON SAID FRAME; THE OTHER END PORTION OF SAID FRAME HAVING AN ANVIL MOUNTED THEREON, SAID ANVIL BEING PROVIDED WITH A FRONT FACE FACING IN THE DIRECTION OF MOVEMENT OF SAID PENETRATOR WHEN MOVING TO APPLY PRESSURE TO THE TEST-PIECE AND AGAINST WHICH FRONT FACE THE TEST-PIECE IS HELD WHEN BEING TESTED, MEANS ENCOMPASSING AT LEAST PART OF THE TEST-PIECE AND HOLDING SAID TEST-PIECE AGAINST SAID FRONT FACE OF SAID ANVIL, SAID PIECE-HOLDING MEANS BEING FLEXIBLY CONNECTED TO THE OTHER END OF SAID C-FRAME AT A POSITION OPPOSITE SAID FRONT FACE OF SAID ANVIL SO THAT THE TEST-PIECE IS PRESSED AGAINST SAID ANVIL UNIFORMLY, SAID ANVIL BEING FORMED WITH A PASSAGEWAY THROUGH WHICH SAID PENETRATOR EXTENDS TO CONTACT THE TEST-PIECE, WHEREBY THE PRESSURE APPLIED TO THE TEST-PIECE, IN BEING TESTED, IS APPLIED TO SAID OTHER END PORTION OF SAID C-FRAME AND CAUSES FLEXING OF SAID C-FRAME, SAID PRESSURE MEASURING MEANS PERFORMING ITS OPERATION BY MEASURING THE FLEXURE CAUSED IN SAID C-FRAME BY SAID PRESSURE, SAID MEANS HOLDING AND PRESSING THE TEST-PIECE ON THE ANVIL BEING A C-SHAPED CLAMP HAVING ONE END CONNECTED TO SAID C-FRAME, AND THE OTHER END PROVIDED WITH A SCREW DEVICE ENGAGING THE TEST-PIECE ON THE SIDE THEREOF OPPOSITE SAID ANVIL. 